Lighting device including light-emitting element

ABSTRACT

In accordance with a first aspect of the present inventive subject matter, a lighting device includes light-emitting elements arranged in lines that are extended in parallel with one another, the light-emitting elements being divided into groups each including the same number of light-emitting elements, a first connecting electrode is disposed adjacent to one end portion of the lines extended, a second connecting electrode is disposed adjacent to another end portion of the lines extended, and the light-emitting elements within each group are electrically connected in series with one another by metallic wires and electrically connected in series to the first connecting electrode and to the second connecting electrode. The groups each include the same number of light-emitting elements that are electrically connected in parallel between the first connecting electrode and the second connecting electrode.

RELATED APPLICATIONS

This application is a new U.S. patent application that claims benefit ofJP 2011-265239, filed on Nov. 2, 2011, the entire content of JP2011-265239 is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a lighting device includinglight-emitting elements arranged in lines that are extended in parallelwith one another between a first electrode and a second electrode. Also,the present invention relates to a lighting device includinglight-emitting elements arranged in lines that are extended in parallelwith one another in a circular mounting area between a first electrodeand a second electrode.

BACKGROUND

In recent years, a light-emitting diode (LED) element, which is asemiconductor element, is widely used for backlight, lighting, etc., ofa color display device, a light bulb, lighting equipment, lightingsystem, a headlamp of a vehicle and so on.

A lighting device including a plurality of LED elements arranged in amounting area has been proposed, for example, Patent Document 1:Japanese Unexamined Patent Publication (Kokai) No. 2010-287657.

Hereinafter, a light-emitting portion 1 of a conventional light-emittingmodule shown in FIG. 1 is briefly explained. The light-emitting elements101 each including a pair of element electrodes are disposed in columnsin a zigzag arrangement on light-reflecting layers or separated mountingareas 102 a-102 d. At least some of the light-emitting elements 101 areelectrically connected to one another in series by bonding wires 108 andelectrically connected to electrical conductors 103 a, 103 b, 104 a, 104b, and/or 104 c at both ends of each column.

SUMMARY

In accordance with a first aspect of the present inventive subjectmatter, a lighting device includes light-emitting elements arranged inlines that are extended in parallel with one another, the light-emittingelements being divided into groups each including the same number oflight-emitting elements, a first connecting electrode disposed adjacentto a first end portion of the lines extended, a second connectingelectrode disposed adjacent to a second end portion of the linesextended, and the light-emitting elements within each group areelectrically connected in series with one another by metallic wires andelectrically connected in series to the first connecting electrode andto the second connecting electrode. The groups each include the samenumber of light-emitting elements that are electrically connected inparallel between the first connecting electrode and the secondconnecting electrode.

In accordance with a second aspect of the present inventive subjectmatter, a lighting device includes a substrate that includes a circularmounting area, a first connecting electrode disposed on the substrate,and a second connecting electrode oppositely disposed on the substrateto the first connecting electrode across the circular mounting area, andlight-emitting elements arranged in lines that are extended in parallelwith one another at the circular mounting area of the substrate betweenthe first electrode and the second electrode disposed on the substrateand that include a central line extended in a central portion of themounting area between the first connecting electrode and the secondconnecting electrode and include a line of periphery positioned awayfrom the central line in a perpendicular direction perpendicular to thecentral line, and the light-emitting elements arranged in the centralline outnumbers the light-emitting element arranged in the line ofperiphery. The light-emitting elements in the lines are divided intogroups each including the same number of light-emitting elements, thelight-emitting elements within each group are electrically connected inseries with one another by metallic wires and electrically connected inseries to a first electrode and to a second electrode, and the groupseach include the same number of light-emitting elements are electricallyconnected in parallel between the first connecting electrode and thesecond connecting electrode.

In some embodiments, it is disclosed that there is a group that includesthe light-emitting elements arranged in two or more lines.

Also, in other embodiments, it is disclosed that there is a group thatincludes some of the light-emitting elements arranged in three or morelines.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of a light emitting portion in a conventional LEDlight emitting device.

FIG. 2 is a plan view of a lighting device according to a firstembodiment of the present invention.

FIG. 3 is a cross-sectional view taken along line III-III of thelighting device shown in FIG. 2.

FIG. 4 is a plan view of a lighting device according to a secondembodiment of the present invention.

FIG. 5 is a cross-sectional view taken along line V-V of the lightingdevice shown in in FIG. 4.

FIG. 6 is a plan view of a lighting device according to a thirdembodiment of the present invention.

FIG. 7 is a plan view of a lighting device according to a fourthembodiment of the present invention.

FIG. 8 is a plan view of a lighting device according to a fifthembodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements and/or portions of anelement, these elements and/or portions of an element should not belimited by these terms. These terms are only used to distinguish oneelement from another and/or one portion from another of an element. Forexample, a first element and/or a first portion could be termed a secondelement and/or a second portion, and, similarly, a second element and/ora second portion could be termed a first element and/or a first portion,without departing from the scope of the present invention.

As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention.

As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”,“comprising,” “includes”, “including”, “has” and/or “having” when usedherein, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Also, as used herein, the term “center axis” is an invisible line thatpasses through a center of a designated element and/or portion and shownas a broken line in Figures.

Furthermore, as used herein, the term “light-emitting element” may beused as a light-emitting diode (LED) element including a first electrodeand a second electrode as a bare chip in some embodiments. The bare chipmay be a wafer-level chip. In other embodiments, the term“light-emitting element” may be used as an LED chip including alight-emitting diode (LED) element with a first electrode and a secondelectrode, and a substrate on that the LED element is electricallymounted. The light-emitting element may appear to be a square orrectangular in shape as viewed from above.

A phosphor layer or plate that is configured to receive light emittedfrom the light-emitting element may be disposed in contact with thelight-emitting element or may be disposed above the light-emittingelement. The phosphor layer includes a phosphor that can convert lightemitted from the light-emitting element and emit converted light ofwavelength different from the wavelength of light emitted from thelight-emitting element.

Relative terms such as “below” or “above” or “upper” or “lower” may beused herein to describe a relationship of one element, layer or regionto another element, layer or region as illustrated in the figures. Itwill be understood that these terms are intended to encompass differentorientations of the device in addition to the orientation depicted inthe figures.

Embodiments of the invention now will be described more fullyhereinafter with reference to the accompanying drawings, in whichembodiments of the invention are shown. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. Rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art.

Embodiments of the invention are described with reference to drawingsincluded herewith. Same and/or similar reference numbers refer to sameand/or similar structures throughout. It should be noted that thedrawings are schematic in nature. Not all parts are always shown toscale.

First Embodiment

Hereinafter, configurations of LED light emitting devices in embodimentsof the present invention are explained with reference to the drawings.

FIG. 2 is a plan view of a lighting device 10 according to a firstembodiment of the present invention. As shown in FIG. 2, a lightingdevice 10 includes light-emitting elements 1 arranged in lines that areextended in parallel with one another, the light-emitting elements 1being divided into groups each including the same number oflight-emitting elements 1, a first connecting electrode 6 a disposedadjacent to a first end portion of the lines extended, and a secondconnecting electrode 6 b disposed adjacent to a second end portion ofthe lines extended. The light-emitting elements 1 within each group areelectrically connected in series with one another by metallic wires 8and electrically connected in series to the first connecting electrode 6a at a first end of each group by a metallic wire 8 and to the secondconnecting electrode 6 b at a second end of each group by a metallicwire 8.

For more details, a lighting device 10 includes a substrate 2 thatincludes a circular mounting area 7, a first connecting electrode 6 adisposed on the substrate 2, and a second connecting electrode 6 boppositely disposed on the substrate 2 to the first connecting electrode6 a across the circular mounting are 7, and light-emitting elements 1arranged in lines that are extended parallel with one another at thecircular mounting area 7 of the substrate 2 between the first connectingelectrode 6 a and the second connecting electrode 6 b disposed on thesubstrate 2 and that includes a central line L1 extended in a centralportion of the mounting area 7 between the first connecting electrode 6a and the second connecting electrode 6 b and include a line ofperiphery L5 positioned away from the central line L1 in a perpendiculardirection perpendicular to the central line L1 or a center axis AX ofthe mounting area 7. The perpendicular direction here coincides with adirection of a line III-III extending as shown in FIG. 2. Thelight-emitting elements 1 arranged in the central line L1 outnumbers thelight-emitting element(s) 1 arranged in the line of periphery L5. Inthis embodiment, the number of the light-emitting elements 1 disposed inthe line of periphery L5 is one, but the number of the light-emittingelements 1 disposed in the line of periphery L5 is not limited to this.The number of the light-emitting elements disposed in the line ofperiphery L5 may be two or more.

The light-emitting elements 1 arranged in the lines are divided intogroups G1-G3 each including the same number of light-emitting elements1. In this embodiment the number of light-emitting elements 1 includedin each group is twelve. As shown in this embodiment, the lightingdevice 10 can include a group that includes some of the light-emittingelements arranged in two lines L1, L1′ as group G1. Also, the lightingdevice 10 can include a group that includes some of the light-emittingelements 1 arranged in four lines, for example, as group G2 and groupG3.

The light-emitting elements 1 within each group are electricallyconnected in series with one another by metallic wires 8 andelectrically connected in series to the first electrode 6 a and to thesecond electrode 6 b of the substrate 2.

The groups G1, G2, and G3 each including the same number oflight-emitting elements 1 are electrically connected in parallel betweenthe first connecting electrode 6 a and the second connecting electrode 6b.

The lines further include one or more intermediate lines L2-L4 extendedbetween the first connecting electrode 6 a and the second connectingelectrode 6 b. The one or more intermediate lines L2-L4 are positionedbetween the central line L1 and the line of periphery L5. The one ormore intermediate lines each include light-emitting elements 1.

The number of light-emitting elements 1 disposed in each line decreasesfrom in the central line L1 through in the intermediate lines L2-L4 toin the line of periphery L5. In this embodiment, the central line L1includes six light-emitting elements 1. The first intermediate line L2away from the central line L1 in the perpendicular directionperpendicular to the central line L1 or the central axis AX of thecircular mounting area 7 and is positioned at a left side of the centralline L1 as shown in FIG. 1 includes five light-emitting elements 1. Thesecond intermediate line L3 away from the central line L1 in theperpendicular direction to the central line L1 and is positioned at aleft side of the first intermediate line L2 includes four light-emittingelements 1. The third intermediate line L4 away from the central line L1in the perpendicular direction to the central line L1 and is positionedat a left side of the second intermediate line L3 includes twolight-emitting elements 1. The line of periphery L5 is positioned at aleft side of the intermediate line L4 and includes one light-emittingelement 1. The light-emitting elements 1 included in the intermediatelines L2-L4 are shifted with respect to the light-emitting elements 1included in a neighboring line. In other words, the light-emittingelements 1 included in the intermediate lines L2-L4 are not aligned withrespect to the light-emitting elements 1 included in the neighboringline. A neighboring line of the first intermediate line L2 is, forexample, the central line L1 or the second intermediate Line L3. As aresult, it may be possible to prevent light laterally and/or downwardlyemitted from the light-emitting elements 1 from being shaded by sidesurfaces of light-emitting elements 1 that are disposed in neighboringlines. Also, if the light-emitting elements 1 included in theintermediate lines L2-L4 are shifted with respect to the light-emittingelements 1 included in a neighboring line, it is possible to arrange thelight-emitting elements at the circular mounting area as evenly aspossible.

The light-emitting elements 1 arranged in lines are positionedsymmetrically with respect to a center axis AX of the circular mountingarea 7. In this embodiment, at a left side of the center axis AX of thecircular mounting area 7, the central line L1, the first intermediateline L2, the second intermediate line L3, the third intermediate lineL4, and the line of periphery L5 are disposed between the firstconnecting electrode 6 a and the second connecting electrode 6 b, and ata right side of the center axis AX of the circular mounting area 7, thecentral line L1′, the first intermediate line L2′, the secondintermediate line L3′, the third intermediate line L4, and the line ofperiphery L5 are disposed between the first connecting electrode 6 a andthe second connecting electrode 6 b. The lines L1-L5 and L1′-L5′ areextended along the center axis AX of the circular mounting area 7 asshown in FIG. 2.

In this embodiment, the light-emitting element 1 includes a firstelectrode and a second electrode that are positioned at an upper surfaceof the light-emitting element 1. In the light-emitting elements 1electrically connected in series with one another in each group, thefirst electrode la of a first light-emitting element of thelight-emitting elements 1 is electrically connected by a metallic wireto the second electrode lb of a second light-emitting element of thelight-emitting elements 1, and the second electrode lb of the firstlight-emitting element is electrically connected by a metallic wire tothe first electrode la of a third light-emitting element of thelight-emitting elements 1 in each group, for example.

The light-emitting elements 1 each include a first electrode la and asecond electrode lb positioned at an upper surface of eachlight-emitting element, and the first electrode la of eachlight-emitting element 1 positioned at a side of the first connectingelectrode 6 a disposed on the substrate 2 and the second electrode lb ofeach light-emitting element 1 positioned at a side of the secondconnecting electrode 6 b disposed on the substrate 2. With thisarrangement of the first electrode la and the second electrode lb of thelight emitting element 1, wire bonding connection among thelight-emitting elements 1, the first connecting electrode 6 a and thesecond connecting electrode 6 b can be easier.

Also, in this embodiment, the first connecting electrode 6 a is disposedalong an outline of the circular mounting portion 7, and the secondconnecting electrode 6 b is disposed along an outline of the circularmounting portion 7. An electrically insulating portion 6 e is providedbetween the first connecting electrode 6 a and the second connectingelectrode 6 b.

The first connecting electrode 6 a may include an arc shape along theoutline of the circular mounting portion 7 and the second connectingelectrode 6 b includes an arc shape along the circular mounting portion7. FIG. 3 is a sectional view taken along line III-III of FIG. 2. Asshown in FIG. 3, the substrate 2 further includes an opening 2 a thatpasses through the substrate 2 from an upper surface to a lower surfaceof the substrate 2, and a metal base 5 disposed in contact with thelower surface of the substrate 2. The metal base 5 may include a flatupper surface attached to the lower surface of the substrate 2. Theopening 2 a of the substrate 2 demarcates the circular mounting area inthat the upper surface of the metal base appears, and the light-emittingelements 1 are thermally connected to the upper surface of the metalbase 5. The substrate 2 may include an electrically-insulating material,for example, a resin and/or ceramic. In this embodiment, a frame 3around the mounting portion 7 is provided on the upper surface of thesubstrate 2. The first connecting electrode 6 a and the secondconnecting electrode 6 b may be positioned within the frame 3, and aspace demarcated by the frame 3 is filled with a light-transmittingresin 9. The light-transmitting resin 9 seals the light-emittingelements 1 and electrical connection including metallic wires 8 amongthe light-emitting elements 1 and the first connecting electrode 6 a andthe second connecting electrode 6 b, and is configured to be alight-emitting area of the lighting device 10. The light-transmittingresin 9 may include a phosphor that receives light emitted from thelight-emitting element 1 and emits light in wavelength different fromlight that is directly emitted from the light-emitting element 1.Furthermore, the light-transmitting resin 9 may include alight-diffusing particle to diffuse light. Also, it is possible todispose a first outer connecting electrode 6 c and a second outerconnecting electrode 6 d outside the light-emitting area of the lightingdevice 10 on the substrate 2. The first connecting electrode 6 a can beelectrically connected to the first outer connecting electrode 6 c andthe second connecting electrode 6 b can be electrically connected to thesecond outer connecting electrode 6 d through an electrode pattern (notshown) printed on the substrate 2, for example. The first outerconnecting electrode 6 c and the second outer connecting electrode 6 bmay be electrically connected to electrodes disposed on a mother boardor may be electrically connected to terminals of a lighting bulb, forexample.

As the number of the light-emitting elements 1 included in each linedecreases from a central portion of the circular mounting area 7 to aperipheral portion in a perpendicular direction perpendicular to thecenter axis AX of the circular mounting area 7, the light-emittingelements 1 can be disposed in accordance with the circular shape of themounting area 7.

In this embodiment, there are two central lines L1, L1′ are extended inthe central portion between the first connecting electrode 6 a and thesecond connecting electrode 6 b. The light-emitting elements 1 includedin the two central lines L1, L1′ are configured to be a first group G1.The light-emitting elements 1 within the first group G1 are electricallyconnected in series with one another by metallic wires 8 andelectrically connected in series to the first electrode 6 a and to thesecond electrode 6 b of the substrate 2. At the left side of the centeraxis AX of the circular mounting area 7, the light-emitting elements 1included in a first intermediate line L2, a second intermediate line L3,a third intermediate line L4, and the line of periphery L5 areconfigured to be a second group G2. The light-emitting elements 1 withinthe second group G2 are electrically connected in series with oneanother by metallic wires 8 and electrically connected in series to thefirst electrode 6 a and to the second electrode 6 b of the substrate 2.At the right side of the center axis AX of the circular mounting area 7,the light-emitting elements 1 included in a first intermediate line L2′,a second intermediate line L3′, a third intermediate line L4′ and a lineof periphery L5′ are configured to be a third group G3. Thelight-emitting elements 1 included in the second group G2 and thelight-emitting elements 1 included in the third group G3 are positionedsymmetrically with respect to the center axis AX of the circularmounting area 7.

The number of the light-emitting elements 1 in the first group G1, thenumber of the light-emitting elements 1 in the second group G2, and thenumber of the light-emitting elements 1 in the third group G3 are thesame; twelve in this embodiment. Generally, twelve light-emittingelements 1 electrically connected in series with one another light upbrighter than twelve light-emitting elements 1 electrically connected inparallel with one another. In this embodiment, since the light-emittingelements 1 electrically connected in series with one another in eachgroup, the light-emitting area of the lighting device 10 can emit acertain amount of light. At the same time, since the first group L1, thesecond group L2, and the third group L3 are electrically connected inparallel between the first connecting electrode 6 a and the secondconnecting electrode 6 b, the lighting device 10 can consume loweramounts of power, compared to a lighting device in which all oflight-emitting elements are electrically connected in series to oneanother. Furthermore, with a combination of serial connection andparallel connection, it is possible to prevent from a sudden cutout ofelectricity supply to all of the light-emitting elements.

Also, in this embodiment, the light-emitting elements 1 can be disposedin accordance with the circular shape of the mounting area 7.

In this embodiment, the light-emitting elements 1 is directly mounted onthe upper surface of the metal base 5. The metal base 5 can be made fromaluminum. In this case, the upper surface of the metal base 5 mayinclude a layer of alumite treatment. Also, it is possible to dispose alight-reflecting layer on the layer of alumite treatment of the metalbase 5 at the mounting area 7 and the light-emitting elements disposedon the metal base 5 through the light-reflecting layer. Thelight-reflecting layer may be electrically insulating, but thermallyconductive. Accordingly, heat generated from the light-emitting elements1 can be efficiently released through the metal base 5 to outside of thelighting device 10. Also, as mentioned above, as the first group G1, thesecond group G2, and the third group G3 includes the same number oflight-emitting elements 1, it is possible to drive light-emittingelements in each group under a common drive conditions.

Second Embodiment

FIG. 4 is a plan view of a lighting device 20 according to a secondembodiment of the present invention. A basic configuration of thelighting device 20 in the second embodiment is similar to a basicconfiguration of the lighting device 10 as shown in FIG. 2, and a samereference numeral is attached to a same and/or similar element, portion,line, and/or group, and repeated explanation is omitted. The lightingdevice 20 differs from the lighting device 10 in a configuration aroundthe mounting area 7. In the lighting device 10, the light-emittingelements 1 are directly disposed on the upper surface of the metal base5 that appears in the opening 2 a of the substrate 2 or thelight-emitting elements 1 are disposed on a light-reflecting layerformed on the upper surface of the metal base 5, and therefore, thelight-emitting elements 1 are thermally connected to the metal base 5.On the other hand, the lighting device 20 includes a substrate 2 that ismade from a resin or a ceramic, and a circular light-reflecting layer 4is disposed at a central portion of the substrate 2. In this embodiment,the circular light-reflecting layer 4 demarcates the circular mountingarea 8 of the substrate 2. The circular light-reflecting layer 4 is anelectrically-insulating layer and the light-emitting elements 1 aremounted on the light-reflecting layer 4. The first connecting electrode6 a is disposed on the upper surface of the substrate 2 and the secondconnecting electrode 6 b is oppositely disposed on the upper surface ofthe substrate 2 to the first connecting electrode 6 a across thecircular mounting area 7 that is demarcated by the light-reflectinglayer 4. The circular light-reflecting layer 4 may be a white ceramicpaste layer or a white resist layer. The circular light-reflecting layer4 may be formed by printing the white ceramic paste or the white resist.

Other configurations except the portion mentioned above in the lightingdevice 20 illustrated in FIG. 4 is same or similar to the lightingdevice 10 shown in FIG. 2, for example in arrangement of thelight-emitting elements 1, electrical connection among thelight-emitting elements, the first connecting electrode 6 a, and thesecond connecting electrode 6 b, and so on.

Third Embodiment

Next, FIG. 6 is a plan view of a lighting device 30 according to a thirdembodiment of the present invention. A basic configuration of thelighting device 30 is similar to the basic configurations of thelighting device as shown in FIG. 2 and the lighting device as shown inFIG. 4, and a same reference number is attached to a same and/or similarelement, portion, line, and/or group, and repeated explanation isomitted. The cross-sectional view can be similar to the cross-sectionalview of the lighting device 10, and therefore, omitted.

The lighting device 30 differs from the lighting device 10 in the numberof light-emitting elements 1 disposed at the mounting area 7 and anelectrically-connecting configuration by the wire 8. For more details,in the lighting device 10, the number of light-emitting elements 1disposed in ten lines L1-L5 and L1′-L5′ at the mounting area 7 is 36,and the 36 light-emitting elements 1 are divided into three groups G1,G2, and G3, as shown in FIG. 2. Each group of the three groups G1, G2,and G3 include 12 light-emitting elements 1. On the other hand, in thelighting device 30, the number of light-emitting elements 1 disposed insix lines L1-L3 and L1′-L3′ at the mounting area 7 is 24, and the 24light-emitting elements 1 are divided into two groups G1 and G2. Thelight-emitting elements 1 are arranged in lines L1-L3 and L1′-L3′ thatare extended parallel with one another at the circular mounting area 7of the substrate 2 between the first connecting electrode 6 a and thesecond connecting electrode 6 b. In this embodiment, the central line L1includes five light-emitting elements 1, and the line of peripheryincludes two light-emitting elements 1. The light-emitting elements 1arranged in the central line L1 outnumbers the light-emitting elements 1arranged in the line of periphery L3. In this embodiment, there is oneintermediate line L2 between the central line L1 and the line ofperiphery L3, and the intermediate line L2 includes five light-emittingelements 1 that is the same number of light-emitting elements 1 includedin the central line L1. The light-emitting elements 1 arranged in theintermediate line L2 are shifted with respect to the light-emittingelements 1 arranged in the central line L1.

Also, the light-emitting elements 1 arranged in lines L1-L3 arepositioned symmetrically with respect to a center axis AX of thecircular mounting area as line L1′-L3′. The center axis AX of thecircular mounting area 7 is positioned between the central line L1 andthe central line L1′. The lines L1-L3 are disposed at the left side ofthe center axis AX of the mounting area 7 and the lines L1′-L3′ aredisposed at the right side of the center axis AX.

At the right side of the center axis AX, the central line L1′ includesfive light-emitting elements 1, and the line of periphery L3′ includestwo light-emitting elements 1. The light-emitting elements 1 arranged inthe central line L1′ outnumbers the light-emitting elements 1 arrangedin the line of periphery L3′. Just symmetrical with the left side of thecenter axis AX, there is one intermediate line L2′ between the centralline L1′ and the line of periphery L3′, and the intermediate line L2′includes five light-emitting elements 1 that is the same number oflight-emitting elements 1 included in the central line L1′. Justsymmetrical with the left side of the center axis AX, the light-emittingelements 1 arranged in the intermediate line L2′ are shifted withrespect to the light-emitting elements 1 arranged in the central lineL1′. The lighting elements 1 disposed in the lines L1-L3 and L1′-L3′ aredivided in two groups G1 and G2 each including the same number oflight-emitting elements. In this embodiment, the group G1 and the groupG2 is just divided at the center axis AX of the mounting area 7. Eachgroup includes the same number of light-emitting elements 1, and herethe group G1 includes 12 light-emitting elements 1, and the group G2includes 12 light-emitting elements 1.

Compared to the lighting device 10 as shown in FIG. 2, the lightingdevice 30 may be a lighting device with lower intensity of light, butthe lighting device 30 can be driven by lower power.

Fourth Embodiment

Next, FIG. 7 is a plan view of a lighting device 40 according to afourth embodiment of the present invention A basic configuration of thelighting device 40 in the fourth embodiment is similar to the basicconfiguration of the lighting device 10 shown in FIG. 2 and FIG. 3, anda same reference number is attached to a same and/or similar element,portion, line, and/or group, and repeated explanation is omitted. Thecross-sectional view can be similar to the cross-sectional view of thelighting device 10 shown in FIG. 3, and therefore, omitted.

The lighting device 40 differs from the lighting device 10 in the numberof the light-emitting elements 1 disposed at the mounting area 7 and anelectrically connecting configuration by the wire 8. For more details,in the lighting device 10, the number of light-emitting elements 1disposed at the mounting area 7 is 36, and the 36 light-emittingelements 1 disposed in ten lines L1-L5 and L1′-L5′ at the mounting area7 are divided into three groups G1, G2, and G3, as shown in FIG. 2. Eachgroup of three groups G1, G2, and G3 include 12 light-emitting elements1. On the other hand, in the lighting device 40, the number oflight-emitting elements 1 disposed in ten lines L1-L5 and L1′-L5′ at themounting area 7 is 48, and the 48 light-emitting elements 1 are dividedinto four groups G1, G2, G3, and G4. Each group of the four groups G1,G2, G3, and G4 include 12 light-emitting elements 1. The light-emittingelements 1 are arranged in lines L1-L5 and L1′-L5′ that are extendedparallel with one another at the circular mounting area 7 of thesubstrate 2 between the first connecting electrode 6 a ant the secondconnecting electrode 6 b. As shown in this embodiment, the lightingdevice 40 can include a group that includes some of the light-emittingelements arranged in two or more lines. For more details, the firstgroup G1 includes seven light-emitting elements 1 arranged in the firstline L1 and five light-emitting elements 1 arranged in the second lineL2, however the third group G3 includes one light-emitting element 1arranged in a first intermediate line L2 and five light-emittingelements 1 arranged in a second intermediate line L3 and fourlight-emitting elements 1 arranged in a third intermediate line L4 andtwo light-emitting elements in the line of periphery L5. The secondgroup G2 and the fourth group G4 are arranged symmetrically with thefirst group G1 and the third group G3. Compared to the lighting device10 shown in FIG. 2 under a common drive condition, the lighting device40 can be a lighting device with higher intensity of light, and requireshigher power.

Fifth Embodiment

Next, FIG. 8 is a plan view of a lighting device 50 according to a fifthembodiment of the present invention. A basic configuration of thelighting device 50 in the fifth embodiment is similar to the basicconfiguration of the lighting device 10 of the first embodiment as shownin FIG. 2 and FIG. 3 and to the basic configuration of the lightingdevice 40 of the fourth embodiment as shown in FIG. 7, and a samereference number is attached to a same and/or similar element, portion,line and/or group, and repeated explanation is omitted. Thecross-section sectional view can be similar to the cross-sectional viewof the light-emitting device 10 shown in FIG. 3, and therefore, omitted.

The lighting device 50 differs from the lighting device 40 shown in FIG.4 in the number of the light-emitting elements 1 disposed at themounting area 7 and an electrically connecting configuration by the wire8. For more details, in the lighting device 40, the number of thelight-emitting elements 1 arranged in the circular mounting area 7 is 48and the 48 light-emitting elements 1 disposed in ten lines L1-L5 andL1′-L5′ at the mounting area 7 are divided into four groups G1, G2, G3,and G4. Each group of the four groups G1, G2, G3, and G4 include 12light-emitting elements 1. On the other hand, in the lighting device 50,the number of light-emitting elements 1 arranged in the mounting area 7is 60, and the 60 light-emitting elements are divided into five groupsG1, G2, G3, G4, and G5. Each group of the five groups G1, G2, G3, G4,and G5 include 12 light-emitting elements. The number of thelight-emitting elements 1 disposed in the circular mounting area 7 ofthe lighting device 50 is larger than the number of the lighting device40. Also, the number of groups each including the same number oflight-emitting elements 1 is larger than the number of groups of thelighting device 40. Compared to the lighting device 40 shown in FIG. 7under a common drive condition, the lighting device 40 can be a lightingdevice with higher intensity of light and, requires higher power.

As described above, it is possible to combine a serial connection and aparallel connection of light-emitting elements 1, in accordance with arequired light of intensity and/or power consumption for a lightingdevice. Also, it is disclosed that the light-emitting elements at acircular mounting area 7 can be disposed as evenly as possible,according to embodiments of the present invention.

Furthermore, while certain embodiments of the present inventive subjectmatter have been illustrated with reference to specific combinations ofelements, various other combinations may also be provided withoutdeparting from the teachings of the present inventive subject matter.Thus, the present inventive subject matter should not be construed asbeing limited to the particular exemplary embodiments described hereinand illustrated in the Figures, but may also encompass combinations ofelements of the various illustrated embodiments.

Many alterations and modifications may be made by those having ordinaryskill in the art, given the benefit of the present disclosure, withoutdeparting from the spirit and scope of the inventive subject matter.Therefore, it must be understood that the illustrated embodiments havebeen set forth only for the purposes of example, and that it should notbe taken as limiting the inventive subject matter as defined by thefollowing claims. The following claims are, therefore, to be read toinclude not only the combination of elements which are literally setforth but all equivalent elements for performing substantially the samefunction in substantially the same way to obtain substantially the sameresult. The claims are thus to be understood to include what isspecifically illustrated and described above, what is conceptuallyequivalent, and also what incorporates the essential idea of theinventive subject matter.

What is claimed is:
 1. A lighting device comprising: a substrateincluding a circular mounting area, a first connecting electrodedisposed on the substrate, and a second connecting electrode oppositelydisposed on the substrate to the first connecting electrode across thecircular mounting area; and light-emitting elements arranged in linesthat are extended in parallel with one another at the circular mountingarea of the substrate between the first connecting electrode and thesecond connecting electrode disposed on the substrate and that include acentral line extended in a central portion of the mounting area betweenthe first connecting electrode and the second connecting electrode andinclude a line of periphery positioned away from the central line in aperpendicular direction perpendicular to the central line, wherein thelight-emitting elements arranged in the central line outnumbers thelight-emitting element arranged in the line of periphery, thelight-emitting elements in the lines are divided into groups eachincluding the same number of light-emitting elements, the light-emittingelements within each group are electrically connected in series with oneanother by metallic wires and electrically connected in series to thefirst connecting electrode and to the second connecting electrode of thesubstrate, and the groups each including the same number oflight-emitting elements are electrically connected in parallel betweenthe first connecting electrode and the second connecting electrode. 2.The lighting device according to claim 1, wherein the lines furtherinclude one or more intermediate lines extended between the firstconnecting electrode and the second connecting electrode and positionedbetween the central line and the line of periphery, and the one or moreintermediate lines each include light-emitting elements.
 3. The lightingdevice according to claim 2, wherein the number of light-emittingelements disposed in each line decreases from in the central linethrough in the intermediate line to in the line of periphery.
 4. Thelighting device according to claim 2, wherein the light-emittingelements arranged in lines are positioned symmetrically with respect toa center axis of the circular mounting area.
 5. The lighting deviceaccording to claim 1, wherein the light-emitting elements each includinga first electrode and a second electrode positioned at an upper surfaceof each light-emitting element, and the first electrode of eachlight-emitting element positioned at a side of the first connectingelectrode disposed on the substrate and the second electrode of eachlight-emitting element positioned at a side of the second connectingelectrode disposed on the substrate.
 6. The lighting device according toclaim 1, wherein the first connecting electrode is disposed along anoutline of the circular mounting portion and the second connectingelectrode is disposed along the outline of the circular mounting portionwith an electrically insulating portion between the first connectingelectrode and the second connecting electrode.
 7. The lighting deviceaccording to claim 6, wherein the first connecting electrode includes anarc shape along the outline of the circular mounting portion and thesecond connecting electrode includes an arc shape along the outline ofthe circular mounting portion.
 8. The lighting device according to claim2, wherein the group includes the light-emitting elements arranged intwo or more lines.
 9. The lighting device according to claim 2, whereinthe group includes some of the light-emitting elements arranged in threeor more lines.
 10. The lighting device according to claim 1, wherein thesubstrate further includes an opening that passes through the substratefrom an upper surface to a lower surface of the substrate, and a metalbase disposed in contact with the lower surface of the substrate, theopening of the substrate demarcates the circular mounting area in thatan upper surface of the metal base appears, and the light-emittingelements are thermally connected to the upper surface of the metal base.11. The lighting device according to claim 11, wherein the upper surfaceof the metal base includes a layer of alumite treatment.
 12. Thelighting device according to claim 11, wherein the metal base furtherincludes a light-reflecting layer on the layer of alumite treatment. 13.The lighting device according to claim 1, wherein the substrate is anelectrically-insulating material and further includes a circularreflecting layer that is disposed on an upper surface of the substrateand demarcates the mounting area of the substrate.
 14. The lightingdevice according to claim 13, wherein the circular reflecting layer iselectrically-insulating.
 15. The lighting device according to claim 1further comprising: a phosphor layer including a phosphor that isconfigured to receive light emitted from the light-emitting elements.16. The lighting device according to claim 1 further comprising: alight-transmitting resin sealing the light-emitting elements and themetallic wires.
 17. The lighting device according to claim 16, wherein aphosphor is included in the light-transmitting resin.
 18. The lightingdevice according to claim 2, wherein the light-emitting elementsincluded in the intermediate lines are shifted with respect to thelight-emitting elements included in a neighboring line.
 19. A lightingdevice comprising: light-emitting elements arranged in lines that areextended in parallel with one another, the light-emitting elements beingdivided into groups each including the same number of light-emittingelements; a first connecting electrode disposed adjacent to a first endportion of the lines extended; and a second connecting electrodedisposed adjacent to a second end portion of the lines extended, andwherein, the light-emitting elements within each group are electricallyconnected in series with one another by metallic wires and electricallyconnected in series to the first connecting electrode and to the secondconnecting electrode, and the groups each including the same number oflight-emitting elements are electrically connected in parallel betweenthe first connecting electrode and the second connecting electrode. 20.The lighting device according to claim 19, wherein the group includessome of the light-emitting elements arranged in three or more lines.